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SD : File class

openNextFile()

Reports the next file or folder in a directory.

Syntax

file.openNextFile()

Parameters

file: an instance of the File class that is a directory

Returns

char : the next file or folder in the path

Example

#include <SD.h>

File root;

void setup()
{
  Serial.begin(9600);
  pinMode(10, OUTPUT);

  SD.begin(10);

  root = SD.open("/");

  printDirectory(root, 0);

  Serial.println("done!");
}

void loop()
{
  // nothing happens after setup finishes.
}

void printDirectory(File dir, int numTabs) {
   while(true) {

     File entry =  dir.openNextFile();
     if (! entry) {
       // no more files
       Serial.println("**nomorefiles**");
     }
     for (uint8_t i=0; i<numTabs; i++) {
       Serial.print('\t');
     }
     Serial.print(entry.name());
     if (entry.isDirectory()) {
       Serial.println("/");
       printDirectory(entry, numTabs+1);
     } else {
       // files have sizes, directories do not
       Serial.print("\t\t");
       Serial.println(entry.size(), DEC);
     }
   }
}
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See Also

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The text of the Arduino reference is licensed under a Creative Commons Attribution-ShareAlike 3.0 License. Code samples in the reference are released into the public domain.